Fluid-actuated gravity shifting apparatus



Patented Nov. 4

uw .il .ii liem w a u (No Model.)

, M B MILLS FLUID 'AGIUATBD GRAVITY SHIFTING APPARATUS.

UNITED STATES PATENT OFFICE.

MORTIMER B. MILLS, OF CI-IICAGO, ILLINOIS.

FLUID-ACTUATED GRAVITY SHIFTING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 439,884, dated November 4, 1890.

i Application filed May 20 l 1890.

To @ZZ whom t Irl/ty concern:

Be it known that I, MORTIMER B. MILLS, a citizen of the United States, residing at Ohicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in FluidActuated Gravity Shifting Apparatus, of which the following is a specification.

The object of my invention is to provide a simply constructed and reliably, eifectively, and readily operative contrivance for moving an object, appropriately supported to permit the application of my improvement, alternately in opposite directions.

The immediate uses for which I especially intend my improvement are those of operating railway-crossing gates, (whether of the vertically-swinging arm or other variety,) signals, switches, and the like g and as the principle of the operation remains the salue whatever the particular object may be to which my improved apparatus is applied, and since a railroad-crossin g gate of the verticallyswinging-arm variety is one of the objects in connection with whichit is supposed that my improved apparatus may be most commonly used, I herein illustrate and particularly descrihe it in such last-named connection.

The accompanying drawing shows, by a broken sectional view, a railway-crossing gate comprising a hollow post supporting a vertically-swinging barrier or arm and my improved fiuid-actuated gravity shifting apparatus applied as the actuating medium for raising and lowering the arm.

A is the gate-post, and P is the arm pivotally supported thereon at the shaft O, carrying a pulley D. The arm B should be (though not necessarily) Inore or less accurately counterbalanced on opposite sides of its support, as should be every object to be actuated, to raise and lower it by means of my improved contrivance, since thereby, for reasons which will be readily apparent from the description of my improvement and the manner of its operation, it operates the more readily and easily.

E and E are two receptacles, which I prefer to provide of metal in lthe cylindrical s hape illustrated and closed at their ends. The receptacles are suspended from the pulley D by a flexible medium r, as a rope, chain, or cable,

Serial No. 352,464. (No model.)

which should be secured against slipping on the periphery of the pulley, and the receptacles thus hang at opposite sides of the shaft O, which supports them through the medium of the pulley, which,however, may obviously be only a segment. Frein their bases the receptacles E and E intercommunicate through a (preferably flexible) conduit E2, which may be formed of rubber hose. The receptacles and their medium of communication contain a liquid w, (preferably a non-freezing liquid,) which may be readily forced from one of the receptacles through the conduit E2 into the other. This conduit practically unites the two receptacles into one, rendering them substantially the same as if a continuous tube of suitable material and containing a liquid were att-ached at its opposite ends to those of the suspending Inedium r, whereby it would extend across, and thus to opposite sides of;

the support (shaft C) of the object (arm B) to be moved.

F and F are iiexible (as rubber) conduits leading, respectively, into the receptacles E4 and E above the liquid therein, and communicating from their opposite ends with an air-pump G, as through the underground pipes q and q', which may, as is usual in pneumatically-operated gates, lead from a valve I-I, (which may be a three-way valve,) alording controllable communication between the air-pump G and the receptacles E and E', and which, when turned in one direction, opens communication between the pump and the pipe q and between the pipe q', and the outer air and when turned in the opposite direction opens communication between the pump and the pipe q and between the pipe q and the outer air.

The operation is as follows: Supposing the gate-arm B to be in its raised position, as indicated, to lower it the valve is turned to open communication between the pump and the pipe q, when on actuating the pump air is forced through the conduit F into the receptacle E on top of the liquid therein, thereby forcing the liquid through the conduit E2 toward the receptacle E', and throwing or shifting the weight of the liquid to the side of the support C toward which the arm B is to be lowered. This will cause the gravity of the liquid thus shifted to lower the gate-arm, and

IOO

it' the latter be counterbalanced it will readily be seen that it will require the shifting of but a comparatively small quantity of liquid from one side of the center or support C to the other to effect the desired movement vof the object B. To raise the arm B after it has been so lowered, communication of the pump with the pipe q and of the pipe q with the outer air is provided by properly turning the Valve H, when on actuating the pump air is forced upon the liquid in the then lower ofthe two receptacles E', shifting the overhalancing Weight of such liquid to the side of the center C, at which the receptacle Ehangs, and asaconsequence causing the arm B to rise.

From the foregoing description of the manner of applying my invention to operate the gate its operation in any of the other connections will be readily understood Without further description or illustration.

What I claim as new, and desire to secure by Letters Patent, is-

In combination with a pivotally-supported arm B, having a pulley D on its pivotal axis, a iexible suspending medium r on the pulley, receptacles E and E', secured to opposite ends of the suspending medium r and intercommunicating at their bases through a conduit E2, iieXible conduits F and F, leading into the receptacles above the liquid therein, and fluid-pressure mechanism controllably commu nicating with the receptacles, respectively, through the conduits-F and F', the Whole being constructed and arranged to operate substantially as set forth.

MORTIMER B. MILLS.

In presence of-- ARTHUR DYRENFORTH, J. W. DYRENFORTH. 

